Larch Arabinogalactan
What is it? Overview Usage Side Effects and Warnings

What is Larch Arabinogalactan?

Arabinogalactins, substances found in many plants, are long molecules made of the sugars galactose and arabinose linked together in a chain. Arabinogalactan extracted from the Western larch tree (larch arabinogalactan, or LA) has been proposed as an immune stimulant.

Test-tube and animal studies suggest that LA has several potentially positive effects on the immune system. It appears to activate a type of white blood cell called a “natural killer” or NK cell, and perhaps other white blood cells as well, and also possibly alter levels of immune-related substances such as interleukins, interferon, and properdin. 1 2 3 4 On the basis of these findings, LA has been advocated as a supplement for general immune support . However, this recommendation is premature. It is a very, very long way from basic science of this type to evidence that a treatment has real effectiveness. Many plant substances appear to activate the immune system; this may be merely because the immune system regards them as “the enemy,” and mobilizes to fight them. It...

Safety Issues

Based on animal studies and limited evidence in humans, LA appears to be essentially nontoxic. 5 However, like other sources of dietary fiber, LA might lead to colonic problems like bloating and flatulence.

One additional set of potential risks derives from its supposed benefits: If LA does in fact meaningfully stimulate the immune system, it might be dangerous. The immune system is balanced on a knife's edge. An immune system that is too relaxed fails to defend us from infections; an immune system that is too active attacks healthy tissues, causing autoimmune diseases. If LA truly boosts immunity, it might cause or worsen such conditions as lupus , Crohn’s disease , asthma , Graves’ disease , Hashimoto’s thyroiditis , multiple sclerosis ,...